1. Field of the Invention
This invention pertains to band pass amplifier circuits and more particularly to circuits wherein the circuit is operated in both amplifying and non-amplifying states.
2. Description of the Prior Art
Band pass circuits having amplifiers are well known. Such circuits usually comprise an impedance having an L/C ratio designed to pass a predetermined band of signal frequencies when the amplifier is in the amplifying state. However, when the amplifier is in the non-amplifying state, i.e., de-energized, the L/C ratio is changed and the band pass characteristics are correspondingly changed, due to changes in the junction capacitances of the active device, which results in detuning or shifting the pass band. This increases the circuit series impedance across the desired pass band causing significant undesirable attenuation.